Pc build for sims 4,please help!

@xws3qax4wier  The most important other detail is the power supply: you want a quality unit with a little more wattage than is strictly necessary for your build.  For a 5800X and a 3060, 550W is Nvidia's recommendation and is more than sufficient; any upgrade beyond 650W would be a waste of money.  Some custom-build sites don't give much, if any, choice in the matter, and when that's the case, the PSU provided is almost always at or above the level you'd choose for yourself, so it's probably not a concern.  But if you want, feel free to list the options you see once you've chosen the other components.

That goes for the build in general too: I'd be happy to look over a parts list.

For RAM, going above about 3600 MHz isn't going to make a noticeable difference either, so don't bother spending a lot of extra money on something faster.

For storage, unless you want to keep a very large amount of data on your computer, it's less of a headache to have just one drive rather than a smaller SSD and a larger HDD.  Given current prices and the convenience of having extra space, I'd personally go with a 1 TB SSD, which is more than double the space Windows and Sims 4 (plus all the custom content you could download) would ever occupy.  But if you need more storage than that, a 500 GB SSD plus a large HDD could be more cost-effective; the question is whether you find the price difference worth juggling the two drives.

I'd suggest that you not spend extra money on a PCIe 4.0 SSD unless the price difference is trivial.  Sims 4 won't even max out a SATA SSD, which is significantly slower than a PCIe 3.0 model, and the main difference between 3.0 and 4.0 is a few extra seconds of load time when you boot into Windows.  DDR5 RAM (as opposed to DDR4) is in the same category—you'd only notice the difference in benchmarks—but the AMD 5000 series CPUs don't support it anyway.

For the motherboard, you might not have many options, but I really wouldn't worry about it unless you plan on upgrading the computer yourself down the line.  X570 boards are the top-tier options, but they only make a difference if you're going to overclock your CPU or GPU or you'll want to add more components later.  (These generally have more slots than a B450 or 550.)  If you do have a choice, don't get an A-type board (e.g. A520) unless it's from Asus.  The other manufacturers' low-end boards are hit or miss.

Like I said, feel free to list any specific components you're considering for a second opinion.  And remember that most computer components from reputable companies do exactly what they're supposed to, which is work well and last for a long time.  So it's not critical to pick the very best of everything, just options that are good enough.